CompTIA Security+ Question K-92

A system administrator attempts to ping a hostname and the response is 2001:4860:0:2001::68.
Which of the following replies has the administrator received?

A. The loopback address
B. The local MAC address
C. IPv4 address
D. IPv6 address

Answer: D

Explanation:
IPv6 addresses are 128-bits in length. An IPv6 address is represented as eight groups of four hexadecimal digits, each group representing 16 bits (two octets). The groups are separated by colons (:). The hexadecimal digits are case-insensitive, but IETF recommendations suggest the use of lower case letters. The full representation of eight 4-digit groups may be simplified by several techniques, eliminating parts of the representation.

CompTIA Security+ Question J-59

Which of the following protocols allows for the LARGEST address space?

A. IPX
B. IPv4
C. IPv6
D. Appletalk

Answer: C

Explanation:
The main advantage of IPv6 over IPv4 is its larger address space. The length of an IPv6 address is 128 bits, compared with 32 bits in IPv4.

CompTIA Network+ Question B-50

Which of the following describes an IPv6 address of ::1?

A. Broadcast
B. Loopback
C. Classless
D. Multicast

Correct Answer: B

Explanation:
The loopback address is a special IP address that is designated for the software loopback interface of a computer. The loopback interface has no hardware associated with it, and it is not physically connected to a network. The loopback address causes any messages sent to it to be returned to the sending system. The loopback address allows client software to communicate with server software on the same computer. Users specify the loopback address which will point back to the computer’s TCP/IP network configuration.
In IPv4, the loopback address is 127.0.0.1.
In IPv6, the loopback address is 0:0:0:0:0:0:0:1, which can be shortened to ::1